Astronomy:NGTS-3

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Short description: Binary star in the constellation Columba.

Coordinates: Sky map 06h 17m 46.75s, −35° 42′ 23.05″

NGTS-3
Observation data
Equinox J2000.0]] (ICRS)
Constellation Columba
Right ascension  06h 17m 46.75s[1]
Declination −35° 42′ 23.05″[1]
Apparent magnitude (V) 14.67±0.01[2]
Characteristics
Spectral type G6 V + K1 V
B−V color index +0.77[2]
R−I color index +0.36[2]
Astrometry
Radial velocity (Rv)8.57±0.05[3] km/s
Proper motion (μ) RA: -8.838[1] mas/yr
Dec.: +8.771[1] mas/yr
Parallax (π)1.3153 ± 0.0193[1] mas
Distance2,480 ± 40 ly
(760 ± 10 pc)
Details[3]
A
Mass1.02±0.09 M
Radius0.93±0.23 R
Luminosity0.72±0.03[1] L
Surface gravity (log g)4.45[4] cgs
Temperature5,600±150 K
Metallicity [Fe/H]0.12±0.15 dex
Rotational velocity (v sin i)1.0±0.7 km/s
Other designations
Database references
SIMBADdata
Exoplanet Archivedata
Extrasolar Planets
Encyclopaedia
data

NGTS-3 is a star located in the southern constellation Columba. With an apparent magnitude of 14.67, it requires a powerful telescope to observe. However, NGTS-3 is actually an unresolved spectroscopic binary. The system is located 2,480 light years away based on parallax, but is drifting away with a radial velocity of 8.57 km/s.

Properties

The system contains two main sequence stars of classes G6 and K1 respectively; only the primary properties is known. NGTS-3A has a similar mass to the Sun, but is 7% smaller. It radiates at 72% the Sun's luminosity from its photosphere at an effective temperature of 5,600 K, which gives it a typical yellow hue of a G-type star.

Planetary System

In 2018, the NGTS survey discovered an inflated hot Jupiter orbiting NGTS-3A despite the components being visually unresolved.[3]

The NGTS-3A planetary system[3]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b 2.38 ± 0.26 MJ 0.023+0.007
−0.005
1.6753728 ± 0.0000030 0? 89.56+0.31
−0.48
°
1.48 ± 0.37 RJ

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 Zacharias, N.; Finch, C. T.; Girard, T. M.; Henden, A.; Bartlett, J. L.; Monet, D. G.; Zacharias, M. I. (February 2013). "The Fourth US Naval Observatory CCD Astrograph Catalog (UCAC4)". The Astronomical Journal 145 (2): 44. doi:10.1088/0004-6256/145/2/44. ISSN 0004-6256. Bibcode2013AJ....145...44Z. https://ui.adsabs.harvard.edu/abs/2013AJ....145...44Z/abstract. 
  3. 3.0 3.1 3.2 3.3 Günther, Maximilian N. et al. (August 2018). "Unmasking the hidden NGTS-3Ab: a hot Jupiter in an unresolved binary system". Monthly Notices of the Royal Astronomical Society 478 (4): 4720–4737. doi:10.1093/mnras/sty1193. ISSN 0035-8711. Bibcode2018MNRAS.478.4720G. https://ui.adsabs.harvard.edu/abs/2018MNRAS.478.4720G/abstract. 
  4. Stassun, Keivan G. et al. (October 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256. Bibcode2019AJ....158..138S.